Non-woven fabric and, a laminate and braided material using the same

Abstract

A non-woven fabric of the present invention is composed primarily of entangled fluoropolymer fibers. In addition, the non-woven fabric of the present invention may be pressure and heat treated, or may be subject to elongation. This provides the non-woven fabric with superior mechanical characteristics.

1 . A non-woven fabric composed primarily of fluoropolymer fibers, wherein the fibers are entangled and the non-woven fabric does not have a foundation cloth.  
     
     
         2 . The non-woven fabric set forth in  claim 1 , wherein an average length of the fluoropolymer fibers is 5 to 50 mm.  
     
     
         3 . The non-woven fabric set forth in  claim 1 , wherein 
 water jet needle punching is performed on a web that is primarily composed of branched fluoropolymer fibers, and an apparent density of the non-woven fabric is between 0.2 g/cm 3  or greater and 1.5 g/cm 3  or lower.    
     
     
         4 . The non-woven fabric set forth in  claim 1 , wherein 
 the non-woven fabric is pressure and heat treated at a temperature at or below the melting point of polytetrafluoroethylene.    
     
     
         5 . The non-woven fabric set forth in  claim 1 , wherein 
 a portion of the fluoropolymer fibers are fused together.    
     
     
         6 . The non-woven fabric set forth in  claim 1 , wherein 
 the fluoropolymer fibers are obtained by uniaxially drawing a fluoropolymer film and then cutting the drawn fluoropolymer film into fibers.    
     
     
         7 . The non-woven fabric set forth in  claim 1 , wherein 
 the fluoropolymer is sintered or semi-sintered polytetrafluoroethylene.    
     
     
         8 . The non-woven fabric set forth in  claim 1 , wherein 
 the fluoropolymer is a ethylene-tetrafluoroethylene copolymer.    
     
     
         9 . The non-woven fabric set forth in  claim 1 , wherein 
 the web further includes one or more types of fibers selected from the group consisting of polypropylene fibers, polyethylene fibers, polyethylene terephthalate fibers, aramid fibers, nylon fibers, poly-para-phenylene benzobisoxazole fibers, polyimide fibers, carbon fibers, glass fibers, alumina fibers, stainless steel fibers, and compound fibers used for splitting.    
     
     
         10 . The non-woven fabric set forth in  claim 1 , wherein 
 the web includes compound fibers used for splitting, and the compound fibers are split.    
     
     
         11 . The non-woven fabric set forth in  claim 1 , wherein 
 the non-woven fabric is elongated to a point at or below a maximum degree of elongation thereof.    
     
     
         12 . The non-woven fabric set forth in  claim 1 , further comprising 
 a support member laminated onto the non-woven fabric.    
     
     
         13 . The non-woven fabric set forth in  claim 1 , wherein 
 the non-woven fabric is twisted to form a braided material.    
     
     
         14 . A method of strengthening a non-woven fabric primarily composed of fluoropolymer fibers, comprising the step of: 
 applying pressure and heat to the non-woven fabric.    
     
     
         15 . A non-woven fabric strengthened by performing the method set forth in  claim 14.